Merge branch 'fix/upgrade-only-menu'

It only appeared when both formulae and casks were outdated; with a
single kind it vanished entirely. Now it shows whenever anything is
outdated, with the empty kind greyed out (autoenablesItems is off —
AppKit would otherwise re-enable the items from the responder chain
on every menu open).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

BrewBar/BrewBarApp.swift

@@ -86,6 +86,9 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         menu.addItem(upgradeAllItem)
         upgradeOnlyItem = NSMenuItem(title: "🎯 Upgrade only…", action: nil, keyEquivalent: "")
         let upgradeOnlySubmenu = NSMenu()
+        // manual isEnabled control below; otherwise AppKit re-enables the
+        // items from the responder chain every time the menu opens
+        upgradeOnlySubmenu.autoenablesItems = false
         upgradeFormulaeItem = NSMenuItem(title: "Formulae", action: #selector(upgradeFormulaeOnly), keyEquivalent: "")
         upgradeCasksItem = NSMenuItem(title: "Casks", action: #selector(upgradeCasksOnly), keyEquivalent: "")
         upgradeOnlySubmenu.addItem(upgradeFormulaeItem)
@@ -570,11 +573,13 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         outdatedSubmenu.removeAllItems()
         outdatedItem.isHidden = outdated.isEmpty
         upgradeAllItem.isHidden = outdated.isEmpty
-        // "only" is meaningful only when both kinds are outdated; with a
-        // single kind, the main item already upgrades exactly what there is
-        upgradeOnlyItem.isHidden = outdated.formulae.isEmpty || outdated.casks.isEmpty
-        upgradeFormulaeItem.title = "Formulae (\(outdated.formulae.count))"
-        upgradeCasksItem.title = "Casks (\(outdated.casks.count))"
+        // visible whenever anything is outdated; a kind with nothing to
+        // upgrade stays listed but greyed out
+        upgradeOnlyItem.isHidden = outdated.isEmpty
+        upgradeFormulaeItem.title = outdated.formulae.isEmpty ? "Formulae" : "Formulae (\(outdated.formulae.count))"
+        upgradeFormulaeItem.isEnabled = !outdated.formulae.isEmpty
+        upgradeCasksItem.title = outdated.casks.isEmpty ? "Casks" : "Casks (\(outdated.casks.count))"
+        upgradeCasksItem.isEnabled = !outdated.casks.isEmpty
 
         for package in outdated.all {
             let item = NSMenuItem(title: package.label, action: #selector(upgradeSingle(_:)), keyEquivalent: "")